1. Field
The present disclosure relates generally to the implantable portion of implantable cochlear stimulation (or “ICS”) systems.
2. Description of the Related Art
ICS systems are used to help the profoundly deaf perceive a sensation of sound by directly exciting the intact auditory nerve with controlled impulses of electrical current. Ambient sound pressure waves are picked up by an externally worn microphone and converted to electrical signals. The electrical signals, in turn, are processed by a sound processor, converted to a pulse sequence having varying pulse widths and/or amplitudes, and transmitted to an implanted receiver circuit of the ICS system. The implanted receiver circuit is connected to an implantable electrode array that has been inserted into the cochlea of the inner ear, and electrical stimulation current is applied to varying electrode combinations to create a perception of sound. A representative ICS system is disclosed in U.S. Pat. No. 5,824,022, which is entitled “Cochlear Stimulation System Employing Behind-The-Ear Sound processor With Remote Control” and incorporated herein by reference in its entirety.
As alluded to above, some ICS systems include an implant, a sound processor unit (e.g., a body worn processor or behind-the-ear processor), and a microphone that is in communication with the sound processor unit. The implant communicates with the sound processor unit and, to that end, some ICS systems include a headpiece, with a microphone, that is in communication with both the sound processor unit and the implantable device. The headpiece communicates with the implantable device by way of a transmitter (e.g., an antenna) on the headpiece and a receiver (e.g., an antenna) on the implant. Optimum communication is achieved when the transmitter and the receiver are aligned with one another. To that end, the headpiece and the implant include respective positioning magnets that are attracted to one another, and that maintain the position of the headpiece transmitter over the implant receiver.
One issue associated with ICS systems is that it is sometimes necessary to remove the magnet from the cochlear implant and then reinsert the magnet into the cochlear implant. Removal and reinstallation of the magnet preferably occurs in situ, i.e., with the cochlear implant secured to bone and accessed by way of an incision in the skin. For example, magnets are not compatible magnetic resonance imaging (“MRI”) systems. Surgical procedures may be performed before and after the MRI procedure to remove and then replace the implant magnet, thereby obviating the need to remove and replace the entire implant. To that end, the implant includes a pocket formed from a resilient material (e.g., silicone) and an opening that is configured to stretch and permit surgical removal and replacement of the implant magnet.
The present inventors have determined that conventional instruments for removing and replacing the implant magnet are susceptible to improvement. For example, the present inventors have determined that it would be desirable to provide instruments that, as compared to conventional instruments, facilitate smaller surgical incision sizes and decrease the likelihood that the resilient pocket will be damaged during magnet removal and installation.